Effect of UV-B radiation on photosynthetic pigments and UV-absorbing compounds of three different soybean cultivars (Glycine max L.).

The effects of UV-B radiation on the amount of chlorophyll a, b, carotenoids, flavonoids, anthocyanins, and polyphenols of three soybean cultivars was studied. After germination in the incubator, plants were put in pots of soil and during 3 weeks and irrigated with Hoagland solution every day. After 3 weeks, plants were exposed to UV-B for 20 min every day for a week. In each cultivar, UV-B reduced chlorophyll a, b, and carotenoids and increased anthocyanins, flavonoids, and polyphenols. The reduction of chlorophyll a and b content was significant between two cultivars Williames, Linfored and L17, Linfored. Carotenoids content showed significant decrease between cultivars Linfored, Williames and Linfored, L17. The anthocyanin and flavonoid contents were affected by UV-B and there was a significant difference in the increase between Williames and L17 and also between L17 and Linfored cultivars. Also increase in phenol content was significantly different between Williames and L17 and also between Williames and Linfored cultivars.